This study has focused on the importance of teacher leadership as power of reform to qualitatively change and to substantially solve problems in schools and researched the potential to develop teacher leadership through ‘practice’ and ‘learning’ of situational context in teacher community. For this purpose, this study has conducted in-depth interviews and teaching observation aimed at 20 teachers of elementary and middle school who has participated in teacher community to cooperatively develop the curriculum and improve a lesson. Then, it has been analyzed based on grounded theory approach of Strauss & Corbin(1998). AS a result of analysis, teachers were immersed into collective intelligence and experienced self-regulating class design in the process of restructuring curriculum. In this process, teachers improved their expertise and communication skills, and established the identity through relationship formation, reflective introspection, daily learning, emotional enhancement, identity awareness, leading to developing shared leadership based on communication and cooperation. Also, development types of teacher leadership(passive, formality, transition, pioneer, assistant, leader) vary depending on parametric condition including various experiences and interaction in teacher community for curriculum reorganization. This study has identified the potential as practice community of teacher for reorganizing the curriculum based on specific process to change themselves and develop their leadership through leadership learning in the context of school teachers live in reality.